... . During NREM sleep your brain activity slows down. There are all together four stages of NREM sleep. NREM sleep begins after the first 90 minutes of sleep. The entire NREM sleep process takes in between fifty and seventy minutes. During stage 1 of NREM sleep there is a mixture of alpha and theta brain waves. When stage 2 begins, there are sleep spindles, K complexes, and ... the final stage of NREM sleep, stage 4, all that is present are the delta brain waves. Stage 1 usually only lasts for a few minutes, while stage 2 lasts for about fifteen to twenty minutes. Stages 3 and 4 can last u...

• Word Count: 2563
• Approx Pages: 10
• Grade Level: High School